The field experiments proposed should allow us to exploit to the utmost the potential for controlled experimentation in a naturalistic field setting. We are continuing to do research in the laboratory with the behavior of white-crowned sparrow, but have become convinced that field experimental methods can yield more precise results than it is possible to obtain in the laboratory with wild animals in captivity. In this way we will establish the generality of the parameters relating to habituation which have been developed in the behavior laboratory and with physiological preparations. We will also investigate the communicative effectiveness of laboratory developed songs, of the songs of different races, and the songs of different dialect groups.